The present disclosure relates to a toner case and an image forming apparatus provided with the toner case.
An electrographic image forming apparatus carries out the development process by supplying a toner (a developer) from a development device to an electrostatic latent image formed on the surface of a photosensitive drum or the like. The toner used in such development process is supplied from a toner case to the development device.
The aforementioned toner case usually includes a case main body that contains the toner and an agitating member that agitates the toner contained in the case main body by rotating along an inner surface of the case main body. Besides, the agitating member is usually made of a synthetic resin film such as a PET film (polyethylene terephthalate film).
However, if the agitating member is made of a synthetic resin film as described above, the agitating member becomes weak in resilience so that when the agitating member rotates, the rotation track of the agitating member deviates from the designed rotation track. As a result, the agitating member fails to reach a corner part of the case main body, and therefore a large amount of the toner will be left in the toner case (hereinafter, referred to as “used case”) having ceased to be of use. Incidentally, this drawback will be improved to some extent if the agitating member is made strong in resilience. However, this will give rise to a new undesired effect that the agitating member produces large noises as it flips on the case main body when the toner in the case main body is nearly run out.
Besides, when the case main body is to be produced, it is a general practice to insert a core (movable mold) into a recess part formed in a cavity (stationary mold) and thus mold the case main body between the cavity and the core. In the case where such a molding method is adopted, it is usually the case that the contact area between the cavity and the case main body is larger than the contact area between the core and the case main body. Due to such a difference of the contact areas, the resistance that occurs when the case main body, after being molded, is released from the molds differs greatly between the cavity side and the core side. Therefore, there occurs a problem that the case main body, after being molded, cannot be released from the cavity, or the molded case main body cannot be easily released from the cavity.